The formulation of detergent compositions which effectively remove a wide variety of soils and stains from fabrics under wide-ranging usage conditions remains a considerable challenge to the laundry detergent industry, in both granular detergents as well as laundry bars. Challenges are also faced by the formulator of automatic dishwashing detergent compositions (ADD's), which are expected to efficiently cleanse and sanitize dishware, often under heavy soil loads. In addition, hard surface cleaners are formulated to sanitize as well as to clean, thereby increasing the need for more potent ingredients in their formulations.
Most conventional cleaning compositions contain mixtures of various detersive surfactants to remove a wide variety of soils and stains from surfaces. In addition, various detersive enzymes, soil suspending agents, phosphorous based and non-phosphorous builders, optical brighteners, and in the case of hard surface cleaners, abrasive materials, are added to boost overall cleaning performance. Many fully-formulated cleaning compositions contain oxygen bleach, which can be a perborate or percarbonate compound. While quite effective at high temperatures, perborates and percarbonates loose much of their bleaching function at low to moderate temperatures increasingly favored in consumer product use. Accordingly, various bleach activators such as tetraethylenediamine (TEAD) and nonanoyloxybenezene-sulfonate (NOBS) have been developed to potentiate the bleaching action of perborate and percarbonate across a wide temperature range.
Most of these prior art bleach activators are solids and are intended primarily as adjuncts to conventional laundry detergent granules. Such laundry granules typically comprise a solid bleach activator in admixture with a coating or carrier material which serves to enhance the stability of the bleach activator and to facilitate its uniform dispersion in the granular detergent. Different from the solid bleach activators known heretofore, another class of bleach activators which have now been found to provide good bleaching of textiles and fabrics, especially on hydrophobic stains, are hydrophobic liquid bleach activators. Such liquid bleach activators are often substantially water-insoluble and can be difficult to use in granular cleaning compositions or bars because they are oily, hydrophobic liquids at ambient temperatures and tend not to solubilize/disperse satisfactorily in the wash water. Indeed, in the case of laundry detergents, an unsolubilized liquid bleach activator can separate from the wash liquor as an oily liquid and fail to be converted to peracids, or can even ultimately cling to the fabrics in the wash where they react with the peroxygen bleach and spot or remove color from the fabrics.
Therefore, the need remains for a suitable liquid bleach activator delivery system for granular or solid laundry detergent compositions.